Indeed, practice makes you perfect, as the more you practice, the more understanding you will attain maturity as a photographer. Your eyes will be more accustomed to catch mistakes and hence you would be able to remove them in your next shot.
For more perfection, you may register for model training courses to learn every bit of modeling and photography practically. This can also help you to excel in your portrait photography career. If you wish to seek any help in getting assignments related to your interest, approaching a renowned agency in the fashion domain could be worthwhile.